Provided is a slope measuring apparatus that accurately measures a slope by attaching a simple structure forming a visually identifiable sign such as a carved line, a printed line, a sticker or a hole to an object of a bar shape. The slope measuring apparatus includes a bar having a marking point (PC) on a location where a user's eyes direction AC with respect to a reference point C separated in the same distance as a predetermined reference distance (Dcal) from a user location on a horizontal plane meets the bar that is arranged side by side with a gravity direction in the same separated distance as an arm length (Darm) in the horizontal direction.

[Claim 1] A slope measuring apparatus, comprising: a bar having a marking point (Pc) on a location where a user's eyes direction AC with respect to a reference point C separated in the same distance as a predetermined reference distance (Dcal) from a user location on a horizontal plane meets the bar that is arranged side by side with a gravity direction in the same separated distance as an arm length ( Darm) in a horizontal direction, wherein a degree of slope of the ground is measured by using a marking point (Pc) and another marking point (Pc) formed on the bar by an eyes direction AC when any measuring point C for measurement on a ground having a slope angle θ is selected.

[Claim 2] The apparatus of claim 1, wherein the bar comprises: a visual field aligning device including a pair of identification signs that is formed on the bar and is realized as a visually identifiable sign to regularly maintain an eyes height (Heye) of an eye starting point and a distance ( Darm) between the eye starting point and the bar, wherein the identification signs are separated to each other in a length direction of the bar and is formed of having a slope to each other in a direction vertical to the length direction of the bar.

[Claim 3] The apparatus of claim 2, wherein the identification signs are formed not to be aligned to a horizontal direction(a direction vertical to the gravity direction).

[Claim 4] The apparatus of claim 2, wherein the identification signs are formed of at least one shape selected from a group consisting of a thorough hole, a groove line, a swelling line, and a gradation line.

[Claim 5] The apparatus of claim 2, wherein the bar comprises: at least one reference sign that is formed on at least one marking point

(Pc) corresponding to at least one value of a slope angle θ of the ground with respect to the reference distance (Dcal) determined by the visual field aligning device and realized as being a visually identifiable sign.

[Claim 6] The apparatus of claim 5, wherein the reference sign is formed of at least one shape selected from a group consisting of a thorough hole, a groove line, a swelling line, and a gradation line.

[Claim 7] The apparatus of claim 1, wherein the degree of slope is determined by whether the slope is uphill or downhill or whether the slope is gradual or rapid based on a predetermined reference or is converted into a numerical value of an accurate slope angle of the ground.

[Claim 8] The apparatus of claim 1, wherein the slope measuring apparatus measures the slope of the ground by using an equation below. where,

A: starting point

C: reference point

C: measuring point

Pc : marking point, i.e., an intersecting point of a straight line AC and the bar

Pc: measurement marking point, i.e., an intersecting point of the straight line AC and the bar

B: intersecting point of a horizontal line from the starting point A and a vertical line from the reference point C

B': intersecting point of the horizontal line from the starting point A and the vertical line of the reference point C

Dcal: reference distance, i.e., a horizontal distance of from a location of user on the ground to the point C

Darm : arm length, i.e., a distance between the user and the bar

Hcal: height of a marking point, i.e., a distance between a horizontal line

AB and the marking point (Pc)

Htarget: height of a measurement marking point, i.e., a distance between the horizontal line AB and the measurement marking point (Pc)

[Claim 9] The apparatus of claim 1, wherein the slope measuring apparatus measures the slope of the ground by using an equation below. where,

A: starting point

C: reference point

C: measuring point

Pc : marking point, i.e., an intersecting point of a straight line AC and the bar

Pc: measurement marking point, i.e., an intersecting point of the straight line AC and the bar

B: intersecting point of the horizontal line from the starting point A and the vertical line from the reference point C

B': intersecting point of the horizontal line from the starting point A and the vertical line of the reference point C

Dcal: reference distance, i.e., a horizontal distance of from the location of user on the ground to the point C

Dmv: slope moving distance, i.e., a distance from an initial location to a point that eyes meet the marking point (Pc) by fixing an end point of the eyes at the measuring point C and moving along the sloping side, θ: slope angle of the ground.

[Claim 10] The apparatus of claim 1, wherein the slope measuring apparatus measures the slope of the ground by using an equation below. where,

Heye: eye height Darm: arm length, i.e., a distance between the user and the bar D: distance between two points whose slope needs to be measured.

where, the above Equation is induced from an equation on ΔH, and θ: slope angle of the ground.

[Claim 11] The apparatus of claim 1, wherein the slope measuring apparatus measures the slope of the ground by using an equation below. where,

Heye: eye height

Htarget: height of a measurement marking point when there is no slope

Hb: height of the measurement marking point when there is a slope

Darm : arm length, i.e., a distance between the user and the bar

D: distance between two points whose slope is to be measured. where, the above Equation is induced from an equation on ΔH, and θ: slope angle of the ground.

[Claim 12] The apparatus of claim 1, wherein the slope measuring apparatus measures the slope of the ground by using an equation below.

where,

Heye: eye height

Htarget: height of the measurement marking point when there is no slope Darm: arm length, i.e., the distance between the user and the bar

D: distance between two points whose slope needs to be measured.

Description:

Description

Title of Invention: SLOPE MEASURING APPARATUS

Technical Field

[1] The present invention relates to a slope measuring apparatus, and more particularly, to an apparatus for simply and accurately measuring a slope by being equipped in an object of a bar shape such as a golf club.

[2]

Background Art

[3] Golf is a complex sport that is sensitively affected by a psychological condition as well as adaptability to external environmental elements of a golfer who selects a club or changes a pitch by determining the external environmental elements that may affect golf such as strength and directions of wind, a ground slope, and a condition of a green in addition to a golfer's basic hitting ability for sending a golf ball in a desired distance and direction by accurate hitting with diverse clubs. In order to actively reduce the number of hitting in golf, improvement in ability of a short game including short iron, approach and putting that are performed around a green is as important as that in hitting ability such as drive and iron.

[4] Environmental elements that most importantly affect the short game are a green and a ground slope. Although ideal hitting is performed by accurate strength in an accurate direction, a ball rolls to an unexpected location when a gradient is wrongly determined. Such a situation gives a golfer a bad point in a hole and seriously affects golfer's psychology over the entire remaining game after receiving the bad point. Therefore, improved judgment on the gradient raises a score and increases interests on golf by providing confidence to golfers.

[5] Although the ground slope may be determined with naked eye, it is difficult to always accurately measure a ground slope direction and a gradient by eye. It is because each person has different sense and a human being basically has optical illusion. An error in determining the gradient due to optical illusion is called mounting break and the mounting break effect increases in a golf course located in a mountainous region. Since there are many cases that it is confusing to judge only a relative height between specific locations with no regard to a degree of the gradient in a location where upward/downward slopes are mixed on a green forming a normal slope, even professional caddies make errors or come into conflict with their golfer to harm a pleasant rounding.

[6] There are many types of equipments for accurately measuring a slope. However, since the conventional slope measuring method is limited only to measurement of the ground slope in a local point having the equipment in a golf green, it has a lot of limitations in usefulness during a game. Also, there are diverse constrains that conventional slope measuring technology is limited to specific technical fields, includes expensive components or needs to minimize disturbance during measurement.

[7] Accordingly, a method and apparatus for conveniently and simply measuring a slope by being equipped in a golf club according to a necessary method that judges a height between two spots and measures a gradient in golf play in a green and around are essentially required.

[8]

[9] Ability in a short game or putting is very important to have a good record in golf and it is necessary to judge a height and a gradient of the lay of the land around to improve the ability. However, since ground gradient judging methods using a gravity direction of a golf club such as Plumb-Bobbing do not have a scientific basis, gradient judgment entirely depends on previous knowledge of the green or golfer's sense. In particular, in case of a green where optical illusion called Mounting Break occurs, it is actually impossible to judge a gradient with naked eye. For example, there is Mystery Road, i.e., Bugaboo's road in Jeju Island. A proper method and apparatus for simply judging a height and a slope value in such lands have not been invented.

[10] Although there are gradient measuring equipments such as a level measuring device and an angle meter, the gradient measuring equipments have limitations that they need to be additionally equipped to be applied to golf to cause inconvenience and using them in a real golf game is violation of regulations. A putter having a slope measuring function by modifying principles of the level measuring device and the angle meter and adding the modifications to the golf equipment has been invented. However, since the putter reduces a performance of putt depending on a very sensitive sense or largely changes a production procedure of a head or a golf club, the putter has many shortcomings that it is not useful in occurrence of errors requiring change of the entire golf club. Accordingly, it is not widely used. Related arts below are examples of technologies that apply the principles of the level measuring device and the angle meter to the golf equipment.

[11] KR Patent Publication No. 2002-0025360, entitled Apparatus for displaying position of golf putter, which is called a related art 1 hereinafter, includes a gradient indicator and a reflector forming a gradation in a putter head to recognize whether the putter head is parallel to the ground by the gradient indicator and estimate an angle between a hitting surface of the putter head and a hole cup by the reflector. KR Utility Publication No. 1995-0026771, entitled Golf club having a gradient measuring structure and shaft or grip, which is called a related art 2 hereinafter, and KR Utility Registration No. 0158897, entitled Green level measuring instrument, which is called a related art 3 hereinafter, measure a slope of a ground by attaching a level or a level measuring instrument on a golf club shaft or a grip.

[12] The related arts use an apparatus for measuring a level, which is simply called a level measuring instrument hereinafter, it is difficult to attach the level measuring instrument to a conventional putter head or golf club. That is, it is possible when the production process of the conventional putter head or the golf club is largely changed and it has a limitation that productivity decreases. It also has a limitation that the entire golf club should be changed when the level measuring instrument is out of order. In particular, attaching the level measuring instrument to the putter head in the same manner as the related art 1 affects a shape, quality of the material, and characteristics of the head affect putting. Accordingly, when the level measuring instrument is attached to the head, many conditions are changed and it may decrease a putting ability.

[13] Technology on a conventional putter for measuring a distance is disclosed. In KR

Patent Registration No. 0717213, entitled Putter with distance measuring function, which is called a related art 4, a distance to a cup is calculated by using a location that eyes and a grip unit intersect when you look at the cup in a state of adjusting a grip end of the putter to eye level and holding the putter in a shape of hanging the putter right over a ball with arms stretched. To be specific, the related art 4 assumes that the distance between eyes and the putt is fixed by an arm length. The distance is calculated through a difference value between eyes and threshold based on geometrical similarity using standing posture, arm stretching, a reference thorough hole formed on the putt/a top surface of the putt/a reference line and eyes. A hitting strength value determined according to the calculated distance is displayed on the putter.

[14] When there is no slope on the ground, progressing distances of balls according to the hitting strength in putting may be the same. However, when there is a slope on the ground, calculation values are largely different. The related art 4 does not provide a unique measure with respect to the ground slope and considers that errors in the distance calculation value generated by the slope may be ignored. However, it is well known that a fine difference in the ground slope substantially has a large effect on the putting. Accordingly, the distance calculation ignoring the slope and hitting strength calculation according to the calculated distance have a large possibility to cause an inaccurate result.

[15] To be specific, the related art 4 is a device for marking gradations on a golf club, measuring a distance between a hole and a golf ball, and determining strength for sending the golf ball to the hole. The device does not provide any information for judging a gradient. It is a well known fact that golfers do not have any problem in calculating a distance between a hole and a ball by eye or strides in putting but feel difficulty in judging a gradient. Therefore, the conventional method does not provide any help in actual golf putting. The conventional method adopts a method for providing hitting strength required for putting by a size of Take-back in a back swing and just suggests logic that putting strength according to the gradient may be naturally compensated when a gradient is small.

[16] In particular, as shown in the title, the related art 4 being a means for measuring a distance as an ultimate object cannot judge a height, a slope value, and a side slope that is the most important variable around a green. In addition, the above method has different results according to physical characteristics. Although a regular distance between eyes and putt should be maintained by regularly maintaining a degree of arm stretching in order to accurately measure the distance, there are few measures for the regular distance and there is a limitation that reproducibility is not secured.

[17] In order to overcome the problem that slope measurement is not possible, the related art 4 additionally includes a device for measuring a slope through a location of an iron ball when the iron ball is put in a vessel of a hemisphere shape and the vessel is put on the ground. This principle is similar to that of the conventional slope measuring apparatus attached to the putter. The problem suggested with respect to the related art 1, i.e., the problem that since shapes, quality of the material, characteristics of the head affect putting, the putting ability may decrease due to a lot of conditions differentiated when the level measuring instrument is attached to the head, still remains. When the related art 4 acquires a compensated hitting strength by using the slope value acquired by using the slope measuring apparatus, the compensated hitting strength has a meaning in a case that a slope is formed in a progressing direction, i.e., a front of a ball. However, when the slope is formed in a direction opposite to the progressing direction of the ball, e.g., a side direction, the compensated hitting strength is meaningless.

[18] The problems of the related art 4 are summarized as follows. First, the related art 4 focuses on measuring of the distance and it is well known that measuring a distance in an actual golf being general information is easy. For example, expensive equipments for measuring an accurate distance and an angle by using Global Positioning System (GPS) are already commercialized. In particular, the equipment for measuring the distance by using GPS may be used in a golf game without causing any problem. However, it is a well known fact that using a distance measuring equipment having a built-in angle measuring function is prevented as being violation of regulations. That is, measuring the distance has no meaning to golfers. Although distance measurement is necessary, it is already possible to accurately measure the distance by using a conventionally commercialized equipment within the regulations in golf.

[19] Next, the related art 4 recognizes that the gradient is an important factor. However, since there is no self-regulating method for solving the problems with related to the gradient, an additional slope measuring means as described above is used. That is, it is avoiding problems with related to the gradient by introducing the concept of the hitting strength. However, there is a limitation that the related art 4 may be applied to the slope of a straight direction of a hole and a ball but may not be applied to a side slope.

[20] The related art 4 also has a limitation that it is not precise or consistent since measurement values vary according to body types.

[21]

Disclosure of Invention Technical Problem

[22] An object of the present invention is to provide a slope measuring apparatus that accurately measures a slope only by adding a simple structure of forming a visually identifiable sign such as a stamp line, a print line, a sticker or a hole to an object of a bar shape such as a golf club.

[23] The object of the present invention will be described in more detail as follows. A distance location between two locations is easily acquired based on distance measurement on a level or Global Positioning System (GPS) but judgment on a height and a slope value is difficult. In particular, judgment on a gradient functions as an essential element for selecting a golf club for sending a golf ball in an appropriate distance or playing a short game including putting well in exercises such as golf. In such a case, the present invention is to provide an apparatus for precisely measuring the height or the slope value by eye only by adding a simple structure to an object of a bar shape such as own golf club. This method enables judging a general gradient of a ground such as a front and a side of a specific location when measured in different angles.

[24]

Solution to Problem

[25] To achieve the object of the present invention, the present invention provides a slope measuring apparatus, including: a bar having a marking point (P c ) on a location where a user's eyes direction AC with respect to a reference point C separated in the same distance as a predetermined reference distance (D cal ) from a user location on a horizontal plane meets the bar that is arranged side by side with a gravity direction in the same separated distance as an arm length (D arm ) in a horizontal direction, wherein a degree of slope of the ground is measured by using a marking point (P c ) and another marking point (P c ) formed on the bar by an eyes direction AC when any measuring point C for measurement on a ground having a slope angle θ is selected.

[26] Preferably, the bar includes: a visual field aligning device including a pair of identification signs that is formed on the bar and is realized as a visually identifiable sign to regularly maintain an eyes height (H eye ) of an eye starting point and a distance (D 31Jn ) between the eye starting point and the bar, wherein the identification signs are separated to each other in a length direction of the bar and is formed of having a slope to each other in a direction vertical to the length direction of the bar.

[27] The identification signs are formed not to be aligned to a horizontal direction, which is a direction vertical to the gravity direction. The identification signs are formed of at least one shape selected from a group consisting of a thorough hole, a groove line, a swelling line, and a gradation line.

[28] The bar includes: at least one reference sign that is formed on at least one marking point (P c ) corresponding to at least one value of a slope angle θ of the ground with respect to the reference distance (D cal ) determined by the visual field aligning device and realized as being a visually identifiable sign. The reference sign is formed of at least one shape selected from a group consisting of a thorough hole, a groove line, a swelling line, and a gradation line.

[29] The degree of slope is determined by whether the slope is uphill or downhill or whether the slope is gradual or rapid based on a predetermined reference or is converted into a numerical value of an accurate slope angle of the ground.

[30] The slope measuring apparatus measures the slope of the ground by using an equation below.

Pl] [32] where,

[33] A: starting point

[34] C: reference point

[35] C: measuring point

[36] P c : marking point, i.e., an intersecting point of a straight line AC and the bar

[37] P c : measurement marking point, i.e., an intersecting point of the straight line AC and the bar [38] B: intersecting point of a horizontal line from the starting point A and a vertical line from the reference point C [39] B': intersecting point of the horizontal line from the starting point A and the vertical line of the reference point C [40] D cal : reference distance, i.e., a horizontal distance of from a location of user on the ground to the point C

[41] D arm : arm length, i.e., a distance between the user and the bar

[46] The slope measuring apparatus measures the slope of the ground by using an equation below. [47] [48]

[49] where,

[50] A: starting point

[51] C: reference point

[52] C: measuring point

[53] P c : marking point, i.e., an intersecting point of a straight line AC and the bar

[54] P c : measurement marking point, i.e., an intersecting point of the straight line AC and the bar [55] B: intersecting point of the horizontal line from the starting point A and the vertical line from the reference point C [56] B': intersecting point of the horizontal line from the starting point A and the vertical line of the reference point C [57] D cal : reference distance, i.e., a horizontal distance of from the location of user on the ground to the point C [58] D mv : slope moving distance, i.e., a distance from an initial location to a point that eyes meet the marking point (P c ) by fixing an end point of the eyes at the measuring point C and moving along the sloping side. [59] θ: slope angle of the ground.

[60] The slope measuring apparatus measures the slope of the ground by using an equation below.

[61] [62] where,

[63] H eye : eye height

[64] D arm : arm length, i.e., a distance between the user and the bar

[65] D: distance between two points whose slope needs to be measured.

[66]

[67] where, the above Equation is induced from an equation on ΔH, and

[68] θ: slope angle of the ground.

[69] Also, the slope measuring apparatus measures the slope of the ground by using an equation below. [70] [71]

[72] where,

[73] H eye : eye height

[74] H target : height of a measurement marking point when there is no slope

[75] H b : height of the measurement marking point when there is a slope

[76] D arm : arm length, i.e., a distance between the user and the bar

[77] D: distance between two points whose slope is to be measured.

[78]

[79] where, the above Equation is induced from an equation on ΔH, and

[80] θ: slope angle of the ground.

[81] The slope measuring apparatus measures the slope of the ground by using an equation below. [82]

[84] where,

[85] H eye : eye height

[86] H target : height of the measurement marking point when there is no slope

[87] D arm : arm length, i.e., the distance between the user and the bar

[88] D: distance between two points whose slope needs to be measured.

[89]

[90] θ: slope angle of the ground.

[91]

Advantageous Effects of Invention

[92] When the present invention is applied, only performing a simple process and marking an identifiable sign on a simple object of a bar shape enables measuring a height between two locations and a gradient of a ground. Accordingly, wrong judgment on the height and inaccurate estimation on a slope value due to optical illusion can be prevented. In particular, when the principle is applied to a golf club, judging a height of a topography and measuring a green slope value can be precisely performed.

[93] In addition, since this apparatus is based on a geometrical principle and does not include additional mechanical/electronic apparatuses, it can be easily added without any physical characteristic change of the existing object such as the golf club. Ac- cordingly, there are advantages that cost for production is low and it is a semipermanent apparatus which does not generate any problem with relation to disorder or repair. [94]

Brief Description of Drawings

[95] The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

[96] FIG. 1 shows a principle of a slope measuring apparatus of the present invention.

[97] FIG. 2 shows a basic form of the slope measuring apparatus of the present invention.

[98] FIG. 3 shows a slope measuring principle in accordance with a first embodiment of the present invention.

[99] FIG. 4 shows a slope measuring principle in accordance with a second embodiment of the present invention.

[100] FIGS. 5 and 6 show a slope measuring principle in accordance with a third embodiment of the present invention.

[101] FIG. 7 shows a slope measuring principle in accordance with a fourth embodiment of the present invention.

[102] FIG. 8 shows a slope measuring principle in accordance with a fifth embodiment of the present invention.

[103] FIGS. 9 to 12 show a slope measuring apparatus in accordance with an actual embodiment of the present invention.

[104] FIG. 13 shows an example that the slope measuring apparatus of the present invention is applied.

[105]

[106] [Detailed Description of Main Elements]

[107] 1: first object

[108] 2: second object

[109] 3: visual field aligning device

[110] 31, 32: identification signs

[111] 4: reference sign

[112]

Best Mode for Carrying out the Invention

[113] Hereinafter, the embodiments of the present invention will be described in detail with reference to accompanying drawings.

[114] FIG. 1 is a basic drawing for describing a principle of a slope measuring apparatus of the present invention. As shown in FIG. l(A), a first object 1 and a second object 2 have a regular gap and suggest an apparatus for forming eyes from the starting point A being a specific point on the first object 1. When there is a reference point C in the same distance as a foreknown reference distance (D cal ) on a horizontal plane with respect to the first object 1, a point that meets the second object 2 in the middle of eyes from the starting point A to the reference point C is a marking point (P c ). That is, the marking point (P c ) is the point that a straight line AC and the second object 2 meet. The starting point A, the reference point C, the marking point (P c ) and the reference distance (D cal ) are pre-designated points or values. That is, when the apparatus of FIG. l(A) is mathematically defined, it is an apparatus marking a point (P c ) on a location that projects eyes looking at the point C, which maintains a foreknown distance, in the point A on the second object 2 in a state of maintaining a correlation between the second object 2 and the point A corresponding to a light source on coordinates (x,y).

[115] FIG. 1 (B) and (C) show a principle of measuring a slope by using the apparatus on a ground forming the slope. When looking at the measuring point C after moving the reference distance (D cal ) from the measuring point C in a topography having a slope, a straight line AC corresponding to the eyes is formed as shown in FIG. 1 (B). A point that the straight line AC and the second object 2 meet is a measurement marking point (Pc). A slope angle θ is acquired from a geometrical relation of the measurement marking point (Pc), the starting point A, the marking point (P c ) and the reference distance (D cal ). Although the calculation is not performed, it is known through a common sense that a ground slope is an upward slope (+θ) of FIG. 1 (B) when the measurement marking point (P c ) is above the marking point (P c ) and the ground slope is a downward slope (θ) of FIG. 1 (C) when the measurement marking point (P c ) is below the marking point (P c ).

[116] FIG. 2 is a basic form of a slope measuring apparatus realized based on the principle as shown in FIG. 1. FIG. 3 shows a slope measuring principle using the basic form in accordance with a first embodiment of the present invention. FIG. 4 shows a slope measuring principle using the basic form in accordance with a second embodiment of the present invention. The first embodiment is a principle inducing a gradient through an eye difference value. The second embodiment is a principle of removing the eye difference value through offsetting by moving in front/back directions according to the gradient when the eye difference value is generated. The slope measuring principles of each embodiment will be described in detail hereinafter.

[117] First, the first embodiment shown in FIG. 3 will be described. In FIGS. 2 and 3 differently from FIG. 1, the second object is located in a vertical direction by gravity. Other things of FIGS. 2 and 3 are the same as those of FIG. 1. According to an actual embodiment, the first object may be a man and the second object may be a golf club.

[118] The starting point A being an eye starting point is an eye location of a man when the first object is the man. A height from the ground to the starting point A is called an eye height (H eye ). Also, a distance between the first and second objects is an arm length of a man when the first object is a man. The distance between the first and second objects is called an arm length (D arm ). Each code shown in FIG. 3 will be arranged as follows. [119]

[120] A: starting point [121] C : reference point [122] C: measuring point [123] P c : marking point, i.e., an intersecting point of a straight line AC and the second object (golf club) [124] P c : measurement marking point, i.e., an intersecting point of the straight line AC and the second object (golf club) [125] B: intersecting point of a horizontal line from the starting point A and a vertical line from the reference point C [126] B': intersecting point of the horizontal line from the starting point A and a vertical line of the reference point C [127] P e : intersecting point of the horizontal line from the starting point A and the second object (golf club)

[128] P f : location point of a hand holding the second object [129] P s : rotation midpoint of a shoulder [130] [131] D cal : reference distance, i.e., a horizontal distance of from the location of the first object (man) on the ground to the point C [132] D arm : arm length, i.e., a distance between the first object (man) and the second object

[139] θ: slope angle of the ground [140] [141] As marked and described in FIGS. 2 and 3, an equation for acquiring the ground slope angle θ by using each of the defined codes will be described as follows. [142] From similarity between ΔABC and ΔAP e P c , a marking point height (H Cal ) is acquired by Equation 1. [143]

[152] Since the eye difference value H is represented by a difference between the marking point height (H cal ) and the measurement marking point height (H target ), Equation 3 being a relation between the eye difference value H and the slope angle θ is acquired. When it is assumed that the slope angle θ is a small value, a sinθ approximates θ and a cosθ approximates 1. Accordingly, a result value of Equation 3 is obtained. Equation 4 below is obtained by arranging the result of Equation 3 and a value of the slope angle θ is obtained thereby.

[153]

[154]

[155]

[156]

[157]

[158] [159] [160] The second embodiment shown in FIG. 4 will be described. The slope angle θ is obtained based on the principle of the first embodiment and also obtained according to another method using the slope measuring apparatus of the present invention. FIG. 4 shows a slope measuring principle in accordance with a second embodiment of the present invention.

[161] In FIG. 4, a method for measuring the slope angle θ is as follows. Other codes in a still state are the same as the definition in FIG. 2 and FIG. 3. A man moves along a sloping side while looking at the measuring point C and stops when his eyes go by the marking point (P c ). A distance that the man moves along the sloping side is a slope moving distance (D mv ).

[162] A point that the starting point A moves the same distance as the slope moving distance (D mv ) along the sloping side is a slope moving starting point (A mv ). A point that the marking point (P c ) moves the same distance as the slope moving distance (D mv ) along the sloping side is a slope moving marking point (P cmv ). Thus, additional codes are defined hereinafter.

[163]

[164] D mv : slope moving distance, i.e., a distance from an initial location to a point that eyes meet the marking point (P c ) by fixing an end point of the eyes at the measuring point C and moving along the sloping side.

[165] A mv : slope moving starting point, i.e., a point that the starting point A moves the same distance as the slope moving distance (D mv ) along the sloping side

[166] P cmv : slope moving marking point, i.e., a point that the marking point (P c ) moves the same distance as the slope moving distance (D mv ) along the sloping side

[167] M: intersecting point of a horizontal line from the slope moving starting point (A mv ) and a vertical line from the reference point C

[168] As shown in Equation 5, lengths of A mv M and MC are obtained.

[169]

[170]

[ 171 ]

[172] [173] Based on similarity of ΔABC and ΔA mv MC, a correlation is obtained as shown in

Equation 6 below. A result as shown in Equation 7 below is obtained when it is arranged with respect to the slope moving distance (D mv ). [174] [175]

[ 176 ] [177]

[178]

[179]

[180]

[181] WWhheenn iitt is assumed that the slope angle θ is a small value, sinθ approximates θ and cosθ approximates 1. Accordingly, a result value of Equation 8 is obtained. Equation 9 below is acquired by arranging the result of Equation 8 and a value of the slope angle θ is obtained thereby.

[182]

[183]

[184]

[185]

[186]

[187]

[188]

[189] As described above with refe the first and second embodiments may be accurately used when a distance between two points is known. When the distance between two points is unknown, a slope may be measured based on a slope measuring principle of following third to fifth embodiments. FIGS. 5 to 8 show each embodiment.

[190] In the third embodiment, a gradient may be measured in the same manner as FIGS. 5 and 6. First, looking into the principle, an eyes marking point is marked on the bar as described above while looking at opposite directions, respectively in two points A and B whose topography height needs to be acquired. The eyes marking point may be marked on the same location if there is no difference in the height between two points. However, when there is a difference in the topography height of two points as shown in FIG. 5 (B), an eyes marking point of the higher point may be marked on a location lower than that of the lower point. A case that the point is lower than the point B as shown in the drawings will be described with reference to the drawings. In this case, a distance H A of the eyes marking point has a smaller value than a distance H B .

[191] FIG. 5 (C) is applied and induced to quantitatively calculate the slope value. H A and H B and a difference ΔH of two values are obtained from each proportional relation of ΔBB 2 A 2 and AAA 3 B 3 . [192]

[193]

[194]

[195]

[196]

[197]

[198]

[199] When the gradient is a small value, tanθ is almost equal to θ. Accordingly, a slope value θ may be measured by an equation such as Equation 11. It will be appreciated that the obtained value ΔH is represented by two times of the eye difference value shown in Equation 4, which is obtained when the distance between two locations is known. Such a relation may be applied in the same manner in FIG. 6 (D). That is, when looking at the points opposite to each other at the point that is away the same distance as a regular distance L from two points, a result as shown in Equation 11 is induced and it may be comfortably applied according to occasions.

[200] In a fourth embodiment, a gradient is measured in the same manner as shown in FIG. 7. As shown in FIG. 7, in the points A and B whose gradient needs to be obtained, a method applying a proportional relation that depends on a difference of the value of the eyes looking at the point that is the same distance as the distance between two points and a distance of D ^1n will described. When an eyes marking point looking at a point C, which is the same distance as the separated distance of the point B from the point A, by stretching out half of the arm length (D arm /2) is the same as an eyes marking point looking at the same point C in the point B by stretching out the arm length (D arm ) from the point B, the land between the points A and B is a flatland having no difference in height. However, as shown in the (B), when the eyes marking point looking at the point C from the point A by stretching out half of the arm length (D arm /2) is different from the eyes marking point looking at the point C from the point B by stretching out the arm length (D arm , ) there is a difference in the height between the points A and B. When the eyes marking point seen at the point B is located above the point B, the land is an uphill slope. When the eyes marking point seen at the point B is located below the point B, the land is a downhill slope. In this case, the eye difference value may be quantified as a gradient value. [201] [202] [203]

[204]

[205]

[206]

[207]

[208] In the fifth embodiment, a

8. As shown in FIG. 8 (A), when a central point of two points is set and seen, a difference value of eyes looking at the two points is a multiple of 2. However, when there is a gradient, the proportional value is not maintained. In this case, the eye difference value may be also quantified as a gradient value.

[209]

[210]

[211]

[212]

[213] This equation being a value related to a human body type H eye is not proper to be quantitatively used in regard to convenience, but is proper to be used in judgment based on a proportion of H a and H m . When the proportion of H a and H m is over 0.5, the land is a downhill slope, and when the proportion of H a and H m is below 0.5, the land is an uphill slope. When the proportion of H a and H m is 0.5, the land is a flatland. That is, it is judged based on Equation 15 below by the principle of the fifth embodiment whether the land is downhill/flatland/uphill.

[214]

[215]

[216]

[217]

[218] The slope measuring apparatus of the present invention may be realized by applying the above-mentioned principle to an object of a bar shape such as an actual golf club. That is, the slope measuring apparatus of the present invention is realized as a bar that the marking point (P c ) is formed at a location where the user's eyes direction AC with respect to the reference point C separated in the same distance as the predetermined reference distance (D cal ) from the user location on a horizontal plane meets the bar that is arranged side by side with a gravity direction in the same distance as the arm length (D arm ) in the horizontal direction. When any measuring point C for measurement on a ground having the slope angle θ is selected, a degree of slope of the ground is measured by using the marking point (P c ) and another marking point (P c ) formed on the bar by the eyes direction AC. The degree of slope is judged according to whether the slope is an uphill slope or a downhill slope or whether the slope is gradual or rapid on the basis of a predetermined reference by using the above-mentioned principle. Otherwise, the degree of slope is calculated as a numerical value of the accurate slope angle of the ground.

[219] The degree of slope includes:

[220] 1. whether the slope is an uphill slope (θ is +) or a downhill slope (θ is -),

[222] 3. what an accurate value of the slope angle θ is. [223] That is, when it is determined whether the slope is an uphill slope or a downhill slope, the above-mentioned predetermined reference may be whether θ is larger or smaller than 0. When it is determined whether the slope is gradual or rapid, the above- mentioned predetermined reference may be whether Iθl is smaller or larger than 3. The above 3 is a numerical value suggested as an example. When the slope measuring apparatus of the present invention is applied to the golf club, Iθl may be properly controlled and determined according to golfer's physical condition. Also, it is possible to accurately find the slope angle θ of the ground based on Equation 4, i.e., the principle of the first embodiment, and Equation 9, i.e., the principle of the second embodiment.

[224] The reason that the degree of slope is defined as being three concepts as described above is that it is not always necessary to know an accurate slope angle. It will be described in detail through specific examples hereinafter.

[225] The degree of slope will be the concept of the number 1 in following cases. For example, when the slope of the golf green is measured by applying the slope measuring apparatus of the present invention to the golf club, it is difficult to judge due to optical illusion whether the slope is an uphill slope or a downhill slope. There is optical illusion that although the road is uphill all the way, human eyes recognize a gradual uphill as a downhill slope when a rapid uphill is changed into the gradual uphill. It is well known to the golfers that the optical illusion occurs frequently. There is a possibility that the golfer may perform wrong judgment due to such optical illusion whether the slope of the golf green is uphill or downhill. In this case, the slope measuring apparatus of the present invention let the golfers simply know whether the slope is uphill or downhill. For example, a golf beginner may increase a putting ability only with the above information.

[226] In a following case, the degree of slope may be the concept of the number 2. In the same example, since golf intermediates have ability to grasp and control own posture for themselves, the golf intermediates grasp the degree of slope, e.g., whether the slope is a gradual slope of 0-3 or a rapid slope of larger than 3, as well as the degree of the uphill/downhill and apply it to the putting.

[227] In a following last case, the degree of slope may be the concept of the number 3. In the same example, professional players such as a pro golfer need to grasp an accurate slope angle to minutely control own posture. Accordingly, an accurate slope angle θ may be measured to be numerically obtained in this case.

[228] As described above, the slope measuring apparatus of the present invention may be used in diverse cases.

[229] Meanwhile, it will be appreciated that it is important to geometrically maintain an object of a bar shape and a starting point where eyes are located in order to precisely evaluate a gradient by accurately realizing the principle. Geometrically maintaining means regularly maintaining the separated distance between the eye starting point and the bar, i.e., arm length ( D arm ), and a height of the eye starting point. In this invention, a visual field aligning device of FIG. 9 is invented and applied to improve reproducibility and accuracy.

[230] The visual field aligning device 3 includes a pair of identification signs 31 and 32 to regularly maintain a height (H eye ) of the eye starting point and a distance (D arm ) between the eye starting point and the bar. The identification signs 31 and 32 are separated to each other in a length direction of the bar, and they are formed of having a slope to each other in a direction vertical to the length direction of the bar. It is preferred that the identification signs 31 and 32 are formed not to be aligned with the horizontal direction, i.e., a direction vertical to the gravity direction. The identification signs 31 and 32 may be formed of any one selected from a group consisting of a thorough hole, a groove line and a swelling line.

[231] As shown in FIG. 9, the identification signs 31 and 32 formed by a small thorough hole or a sign having a same function are made on the bar in a direction of two straight lines having a vertex at the eye starting point by the visual field aligning device 3. Accordingly, when the starting point A and the bar deviate from a right position, the identification signs 31 and 32 are not simultaneously seen.

[232] As shown in FIG. 9 (C), it is also possible to extend usage by forming a plurality of sings such as the identification sign. That is, when the slope whose distance is known is measured, an initial marking point (P c ) varies according to the reference distance. Accordingly, signs such as the identification sign having a right angle are formed more in a proper location to be applied. In order to divide the identification signs 31 and 32 for aligning the visual field, i.e., the identification signs 31 and 32 included in the visual field aligning device 3, from remaining signs, the remaining signs are called a reference sign 4 as a meaning that the remaining signs represent the marking point (P c

)•

[233] Three examples on products of the slope measuring apparatus applying the principle are representatively suggested as shown in FIGS. 10 to 12. A sign is provided by setting a gradation as being an eye difference value with respect to a unit slope value of 1% slope corresponding to an arm length determined by the visual field aligning device by applying that the eyes difference value H and the slope angle θ of the ground are irrelevant to a physical characteristic such as a human height or an eye level and is a value determined by the arm length (D arm ) that a man stretches out. The eye difference value being a value with no regard to an initially set reference distance or an eye level, i.e., a starting point height, which varies according to the human height, is given as follows. [234]

[235] Eq. 16

[236] An eye difference value when a distance between two locations is known, H = θ (%)/100 x D arm

[237] An eye difference value when a distance between two locations is unknown, ΔH = 2*θ (%)/100 x D arm

[238]

[239] That is, when this apparatus invented to maintain the constant arm length by using the visual field aligning device is used in measuring a slope value between two positions whose distance is known, an eye difference value simply becomes a value proportional to a slope angle. In a general ground slope, when the slope angle using a % unit is divided by 100 and multiplied by the arm length, a result value becomes an eye difference value corresponding to a 1% slope value. When the distance between two points is unknown, the eye difference value increases as much as two times by performing measurement at the two points.

[240] In case of most adults of a normal body type including men and women, a gap between eyes and a bar comfortably held by the adult, i.e., an arm length, may range approximately from 40cm to 60cm. A table below shows an example that a relation between two values is calculated by dividing the two values on the basis of 10cm unit. A man who lengthens his arm length may have a large identification gap of the eyes difference value with respect to the same gradient as shown herein. Table 1 below shows a proportional relation of the eye difference value and the slope angle according to a set value of the arm length. It is irrelevant to the body type.

[241]

[242] Table 1

[243]

[244] Accordingly, when the apparatus applying the present invention is made, the visual field aligning device using the principle of FIG. 9 is provided and it may be a device for making it easy to grasp a gradient by providing an eye difference value proper to the visual field aligning device as a gradation for easy identification or providing bands of diverse colors (see FIG. 12). That is, a fact that a difference of one gradation is a 1% gradient is notified by providing a gradation of 0.4cm gap or a band of repeated colors in case of a visual field aligning device made to maintain an arm length of 40cm, a gradation of 0.5cm gap or a band of repeated colors in case of a visual field aligning device made to maintain an arm length of 50cm, and a gradation of 0.6cm gap or a band of repeated colors in case of a visual field aligning device made to maintain an arm length of 60cm. When the unknown distance between two locations is measured in each opponent location, the eye difference value becomes two times. Accordingly, it may be used by multiplying the calculated value by 2. FIG. 13 shows an example of a field that the present invention may be applied. In particular, the present invention may be a unique means for grasping a ground slope as shown in FIG. 13 (B), which has never been invented before.

[245] It will be apparent that the invention is not limited to the embodiments and application fields are diverse. Also, various changes and modifications may be made by those skilled in the art without deviating from the basic concept of the invention as set forth in the appended claims.